Safety paper and process of making the same



Patented Apr. 28, I92? I I UNITED STATES PATENT OFFICE.

CHARLESFRANK SAlHMET, OF DALTON, MASSAQHUSE'ITS, ASSIGNOR TO CRAN'E 86 COMPANY, OF DALTON, MASSACHUSETTS, A PARTNERSHIP.

SAFETY PAPER AND rnoenss or mile THE SAME.

No Drawing.

1 '0 all whom 2 2 may concern: i Be it known that I. CPL-llamas FRANK SAM- )n-z'r, a citizen of the United States, residing at Dalton, in the county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements in Safety Paper and Processes of Making the Same, of

which the following is a description.

My invention relates to an improved processfor the manufacture of safety paper for checks, notes, bonds, wills and other documents, and has for its object the production. of a paper of such character that any attemptto obliterate or remove writing, printing or other marks thereon by chemical means will cause a marked change in the appearance or color of the paper where the chemical has been brought in contact with the surface, as a result of which, changes in the writing or printing or other. marks will be more apparent and the fraud easilydetected.

It will also be understood that the invention is applicable either to plain white or tinted paper, as well as to paper having'surface markings thereon for the purpose of indicating when mechanical erasures of the writing or marking thereon have been made.

In the manufacture of this safety paper by incorporation of the ingredients applied thereto in the body of the paper, I make use of ,any of the usual well known processes for the manufacture of paper, and the material tobe used in the process for making the safety paper, and for the purpose of accomplishing the result, is incorporated in the paper at any desirable stage of the man-- ufactureeither while the paper is in the pulp stage: in the web: or the material may be added during the sizing operation.

The essential feature of the invention consists in the incorporation therewith at any desirable stage in the manufacture of the paper, of a member of the diphenylamin I group, such as diphen vlamin or its homologues. substitution products. derivatives or salts. Of this, I prefer diphenylamin and I find the most useful to be an insoluble saltthereof and of these I prefer the sulphate.

\Vhile, as above stated, the safety material may be incorporated with the paper at any suitable stage in its manufacture. that is. in the pulp. in the web, after or with the sizingit will also be understood that Application filed October 31, 1921. Serial No. 511,809.

it may beapplied as acoating to the otherwise finished paper; or, when desired, it may be applied by incorporating it with the ink used for marking the paper. I also consider the invention broad enough to include the application of the safety material tothe finished paper either in the form of powder or suspended in a liquid or as a solution. In fact, in a co-pending application, 511,808, executed of even date herewith, I have set forth a way of applying the material to the finished paper by molding the material in the form of sticks somewhat analogous in sizeand shape of the well known sticks of shaving soap, the molding being accomplished under pressure or by incorporating a small amount of binder, such as starch, with the material suflicient to hold the particles together. This stick may be rubbed over the paper manually with the exertion of slight pressure and the excess material may then be removed either by blowing or dusting it off. A suflicient amount will remain incorporated in the surfafe of the paper to produce the desired resu t.

When the paper is manufactured by incorporation of the safety material during the process of manufacture of such paper, I have found substantially the following proportions give the best results, viz: 100 parts by weight of pulp to 5 parts of the diphenylamin' salt, although it will be understood that these proportions may be varied with out departing from the spirit of the invention.

The substances of the class named, and especially those substances mentioned, are discolored upon treatment with ink eradicas tors, which usually contain oxidizing agents, the change being due to the oxidizing effect of the eradicator, although other ingredients thereof may also produce a color change in the safety material. A dirty brown spot is usually produced upon the paper with which they are in contact, which spot cannot be obliterated by treatment with acids, alkalis, reducing agents or other chemicals.

I have found that the safetysubstances I propose to use are best used in the'form of insoluble salts, for example, as sulphates, since the color of the diphenylamin or other sulphate or other insoluble salts are practically unaffected by long exposure to light,

While the soluble salts are somewhat darkened by long exposure thereto.

The stain produced by treatment with an oxidizing agent cannot be removed by treatment with acids or alkalis or reducing agents; however, should a reducing agent be present during the treatment with an oxidizing agent the stain may not appear until the reducing agent has been oxidized.

In a co-pending application 511,808,'(1esignated as Case I, I have claimed the process of making safety paper and the product itself having benzidine incorporated therewith, and the application, heretofore referred to as relating to the stick of safety material is designated as Case III application 511,810.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. The process of making safety paper which consists in adding to the paper a material which is a colorless member of the diphenylamin group or its homologues.

2. The process of making safety paper which consists in adding to the paper a salt of the diphenylamin group or homologues thereof.

3. The process of making safety paper which consists in adding to the paper an insoluble salt of diphenylamin.

4. The process of making safety paper which consists in adding to the paper diphenylamin sulphate.

5. The process of making safety paper which consists in adding to the paper diphenylamin sulphate in substantially the following proportions-100 parts by weight of pulp to 5 parts by weight of diphenylamin salt.

6. Paper, having a colorless member of the diphenylamin group incorporated therewith.

7. Paper, having a colorless member of the diphenylamin group incorporated there- 1n.

8. Paper, having a salt of a member of the diphenylamin group incorporated therewith.

9. Paper, having a salt of a member of the diphenylamin group incorporated there- 1n.

10. Paper, having an insoluble salt of a member of the diphenylamin group incorporated therewith.

11. Paper, having an insoluble salt of a member of the diphenylamin group incorporated therein.

12. Paper, having an insoluble compound of a member of the diphenylamin group incorporated therewith.

13. Paper, having an insoluble compound of a member of the diphenylamin group incorporated therein.

14, Paper, having a sulphate of a member of the diphenylamin group incorporated therewith.

15. Paper, having a sulphate of a member of the diphenylamin group incorporated therein. 7

16. Paper, having diphenylamin incorporated therewith.

17. Paper, having diphenylamin incorporated therein.

18. Paper, having a salt of diphenylamin incorporated therewith.

19. Paper, having a salt of diphenylamin incorporated therein.

20. Paper, having'an insoluble compound of diphenylamin incorporated therewith.

21. Paper, having an insoluble compound of diphenylamin incorporated therein.

22. Paper, having an insoluble salt of diphenylamin incorporated therewith.

23. Paper, having an insoluble salt of diphenylamin incorporated therein.

24. Paper, having diphenylamin sulphate incorporated therewith.

25. Paper, having diphenylamin sulphate incorporated therein.

In testimony whereof, I affix my signature.

CHARLES FRANK SAMMET. 

